Mobil 1 Racing 4T 10W-40 motorcycle oil. I think BRP is missing the boat on this oil due to their unfamiliarity with the motorcycle world. Mobil 1 motorcycle oil does indeed meet API spec SM which BRP states should not be used and will cause clutch slippage. However, Mobil 1 motorcycle oil also meets JASO MA which is the holy grail as far as wet clutch performance is concerned. If you own a Honda motorcycle, for example, they specify that the oil must meet JASO MA. That pretty much excludes any regular automotive oil and is a way of specifying that it must be motorcycle oil that has been tested for wet clutch performance. I think BRP is unaware of this spec since they don't live in the motorcycle world. Their concern over API SM is likely based on automotive oils meeting API SM specs which would also state "energy conserving" in the API seal on the bottle. Honda prohibits using any oil with an API "energy conserving" seal on it -- they are too "slippery" for long-lived wet clutch performance. All high-quality automotive oils, even pre-SM oils like SJ or SL had the "energy conserving" seal on them. So according to BRP, you could use one of those automotive oils (SJ or SL energy conserving) and meet their spec while being totally outside Honda's spec. I personally think that is incorrect thinking on their part and what they should be doing is copying Honda and other motorcycle manufacturers. They should be specifying motorcycle oil meeting JASO MA and prohibiting API "energy conserving" in order to assure good wet clutch performance. API SM is not the problem in and of itself. If you look on your Amsoil bottles, Amsoil meets JASO MA and has an API SL rating, not stating "energy conserving". Mobil 1 4T meets JASO MA and has an API SM rating and is not "energy conserving". If you look at automotive oils, you will not find them tested against JASO MA and you will find the better ones to be "energy conserving". Personal anecdotes on oil are highly unreliable in my opinion but I will offer one anyway. I've used predominately Mobil 1 4T, and occasionally Amsoil, in every motorcycle I've owned and had excellent performance. For example, 95,000 miles on a Gold Wing which is a big heavy motorcycle that demands a lot out of a clutch, and not a trace of slippage. That said, you go against BRP recommendations at your own risk.